Public fears related to toxic or pollutant gases being radiated throughout an area have generated development of sensor networks that may provide real-time or near real-time early-warning signs for a wide array of chemical, biological and nuclear threats across the area. Sensor node networks may be deployed throughout cities and towns to measure, monitor, detect and notify the public of bio-events. Example bio-events that might be detected include presence of an intruder or multiple intruders, biological and chemical attacks, spread of infectious diseases, and an increase in pollen concentrations.
Sensors within sensor networks may include micro-electromechanical systems (MEMS) and other nanotechnology based biological and chemical sensors, which interact with one another to perform as peer-to-peer network elements with multilevel security and quality-of-service guarantees, spanning wireless, wired and satellite links, for example. The sensors may provide information to public authorities, which can then notify the public in a vicinity of a region where an infectious disease has been detected, for example. Given the geographically distributed nature of sensors in a sensor node network, a centralized architecture in which all information generated by the large number of sensors is collected by a central entity can become prohibitively expensive and impractical. The central entity would then also need to return a decision to all or some of the sensor nodes that instructs the sensor nodes to take additional action.
Each node in a sensor node network may detect an event by making periodic measurements of variables that help detect presence of the event, and then may make a decision about the presence or absence of the event. Dedicated communication links between pairs of nodes and between the nodes and a central unit are employed to enable the nodes to communicate their measurements and decisions amongst one another. Doing so helps each node to improve an accuracy of a decision. However, establishing communication protocols for use in communication between the sensors individually and for use in communication between the sensors and the central entity can become complicated making the sensor node network less appealing.